Wrap the entire search logic in a try/catch statement

This should effectively turn script-terminating errors into just warnings and
thus at least working-around issue #397: the exceptions will be logged as
warnings intead of errors, but still logged.

exec/imapservice.js

@@ -1851,6 +1851,7 @@ function do_search(args, uid)
 	var result=[];
 	var offsets=index.offsets;
 
+	try {
 		function get_func(args)
 		{
 			var next1,next2;
@@ -2095,6 +2096,9 @@ function do_search(args, uid)
 		}
 
 		untagged("SEARCH "+result.join(" "));
+	} catch(error) {
+		log(LOG_WARNING, "Exception during search: " + error);
+	}
 }
 
 var selected_command_handlers = {